Details

Date

1876

Author

Pasteur

Contribution

a. Cultured an organism and used its "ferment" to make urine ammoniacal.

Reference

Carter

Notes

He cultured the microorganism, precippitated its soluble enzyme ("ferment") and used it to transform diluted urine into ammonium carbonate, in vitro. According to Carter, this "isolation and reinoculation" was a key factor in demonstrating sufficient causality, and an advance over his recent studies on silkworm disease and beer spoilage. At this time (1870s) most physicians assumed that a given disease could have many causes -- any one of which could be a sufficient cause, but not a necessary cause (since alternative causes existed). Carter holds that this view was supported by the newly popular emphasis of pathological anatomy, in which autopsy findings were sufficient to explain clinical symptoms, but which in turn might have had any of a number of causes. Pasteur's experience, in contrast, would have led him to look for one necessary cause, one that would be applicable to every case of a particular disease. The use of pure cultures, as in this study on urine, would be needed to prove that the cause in question would also be sufficient, i.e. able by itself to cause the disease. Carter does not suggesst that Pasteur consciously made such distinctions between types of causality.